1. Field of Invention
The present invention relates to stroller or baby carriages ("rollable child carrier structure") that are constructed of a novel composite material.
2. Brief Description of the Art
Numerous patents are directed to the design and specific materials for strollers and baby carriers. Most involve the use of steel or aluminum frames.
U.S. Pat. No. 5,205,578 involves the use of injected molded; thermoplastic material in strollers. However, certain problems exist with the use of this material in strollers and baby carriages.
These problems include (1) the use of very expensive molding operations and capital costs; (2) the resins specifically cited (i.e., polypropylene and nylon) cannot carry the required loads without massive distortion of the stroller or carriage frame over time or during use unless special and non-readily available thermoplastic resins are used; (3) any thermoplastic resin currently available that can carry the loads without distortions (e.g., polycarbonate resins) are expensive and very difficult to process; (4) thermoplastic resins are generally difficult to paint or coat because of their inherent low surface tension; (5) a plastic stroller annotates a cheaply made item vis-a-vis comparable shaped metal materials; and (6) the use of thermoplastic material that does not distort will have to be very thick.
Thus, a need existed for a stroller or baby carriage made out of a better material than metals or injection molded plastic materials. U.S. Pat. No. 5,702,120 (Malofsky et al.), describes improved materials and an improved design for reliable child carrier structures, such as strollers which overcomes the problems associated with above-described materials. The lightweight, high modulus fiber-reinforced plastic matrix composite tubing materials described in U.S. Pat. No. 5,702,120 provide lightweight, durable, strong, stiff noncorroding parts that feel and sound like metal, and allow for a design that is itself lightweight, of consistent quality, safe, durable and easily folded, stored and transported, all at a relative low cost. While these tubing materials can be used for the vast majority of stroller frame parts and represent a large improvement over the prior art metal and plastic frame parts, there are certain situations where the stroller parts must have more stiffness and be more amenable to different types of fabrication on assembly with either each other or other materials such as fabrics. The present invention offers a solution to those problems.